// Methods
public StreamCtx()
{
this.ibc = null;
this.iv = null;
this.mode = StreamCipher.Mode.CBC;
this.fReadOnly = false;
}
/// <summary>
/// creates the context to be used by the other methods
/// once created the context is readonly
/// use always this method (or its overwrites) to obtain a context
/// </summary>
/// <param name="ibc">this method will call InitCipher, you dot not need to call it before</param>
/// <param name="key">make sure the length of the key is as required
/// some ciphers have key size restrictions</param>
/// <param name="iv">is ignored in EBC mode</param>
/// <param name="mode"></param>
/// <returns></returns>
public static StreamCtx MakeStreamCtx(IBlockCipher ibc, byte[] key, byte[] iv, StreamCipher.Mode mode)
{
StreamCtx ctx = new StreamCtx();
ctx.Ibc = ibc;
ctx.Ibc.InitCipher(key);
ctx.IV = iv;
ctx.Mode = mode;
ctx.MakeReadOnly();
return(ctx);
}
